Numerous documents, some of which are in the name of the present Applicants, are known, which describe reflectors the purpose of which is to achieve the above mentioned criteria.
In particular, French patent specification No. FR 2 536 502A, which corresponds to U.S. Pat. No. 4,530,042 to Cibieet al., discloses a reflector which is mathematically defined in such a way that it positions the various images of a light source, such as a cylindrical filament, below a straight cut-off line, and preferably with the highest points of these images being situated close to the said cut-off line.
Other documents, and in particular U.S. Pat. No. 4,772,988 to Brun, which is again in the name of the present Applicants, discloses reflectors which are adapted to form the same kind of light beam, but with improved photometry and/or improved width.
It should be observed here that a light beam having a substantial width, obtained with the aid of an uncorrected reflector, enables the size of the striations or light diverting prisms formed on the cover lens of the headlamp to be minimised. This is of advantage in the context of styling, and also in terms of optical considerations, especially if the lens is steeply inclined with respect to the vertical, as is often the case in modern vehicles having a sharply plunging front profile.